Spero licenses anti-CD40L antibody SP001 from Innovent in deal worth up to $1.1 billion

Spero Therapeutics and Innovent Biologics announced on July 14, 2026 an exclusive license agreement for SP001 (Innovent's internal code IBI355), a Phase 2-ready third-generation Fc-silent anti-CD40L antibody¹. The underlying agreement was signed on July 8, 2026. Innovent granted Spero an exclusive, sublicensable right and license to research, develop, manufacture, and commercialize SP001 and related backup and derivative CD40L-targeting antibodies worldwide, excluding mainland China, Taiwan, Hong Kong and Macau.¹

Financially, Spero is obligated to pay Innovent a $35.0 million upfront payment, plus aggregate milestone payments of up to approximately $1.05 billion tied to development, regulatory and commercial milestones.¹ Spero also owes Innovent tiered royalties ranging from a high single-digit to a mid-teen-digit percentage on annual net sales.¹

On the clinical front, Spero currently expects to advance SP001 into a Phase 2 trial in patients with IgG4-related disease in the second quarter of 2027.¹ Innovent separately plans to initiate a Phase 2 trial in China for Sjögren's disease by early 2027, with Spero having the option to expand into that indication later.¹ Supporting data so far include two healthy volunteer Phase 1 trials (single and multiple ascending dose) and a Phase 1b multiple ascending dose study in patients with primary Sjögren's disease¹, with results from the Sjögren's study presented at the EULAR 2026 Congress.¹

Separately, Spero closed a royalty financing transaction on July 8, 2026 involving special-purpose subsidiaries. The Issuer sold senior secured notes totaling $105,000,000 in aggregate principal, issued net of a $3,150,000 original issue discount, accruing 10% annual interest, and maturing nine years after closing.¹ The company estimates that combined net proceeds and existing cash will fund operations into the second half of 2029.¹